As the most widely used engineering material at present, concrete plays a role in various fields. Experts of various countries in the world prepare various concretes with unique properties and more application fields by study for exploiting various excellent properties of concretes and satisfying needs of construction and building materials.
With rapid development of industrialization and urbanization, environmental pollution problems have become urgent problem to affect human health and national development. Photocatalytic technique, as a new and environmental protection technology, can degrade some pollutants. In preparation of photocatalytic material, nano titanium dioxide photocatalytic material gained popularity due to characteristics of low cost, stable chemical property, no toxicity and no harm, energy conservation and environment protection and mature preparation technology. Photocatalytic concrete is an efficient way to solve air pollution, and has certain degradation effect on main air pollutants such as nitric oxide and sulfide of automobile exhaust and industrial exhaust.
At present, no companies and enterprises in China have applied photocatalytic concrete successfully. It is still in the research and development stage. However, many experts and scholars in China and abroad have already made some progress in photocatalytic concrete research and development. However, some problems such as low degradation efficiency, poor wear resistance performance, short service cycle and high application cost are existed.
1. Automobile exhausts are assembled on the road surface, however, they are difficult to be adsorbed by common titanium dioxide photocatalytic material, that is, the automobile exhausts cannot be further degraded, resulting in low efficiency of photocatalyst. If materials with good adsorbing effect are added, such as activated zeolite, the automobile exhausts on the road surface can be adsorbed, thereby increasing photocatalytic degradation efficiency of titanium dioxide.
2. Rubber powder and coal ash are used in Chinese patent CN200910185024.8 and CN201110083342.0 respectively as photocatalyst carrier, which realizes waste utilization and has many good performances. However, in industrial production, preparation of rubber powder and screening of coal ash are of big equipment investment and high production cost, so they are difficult to be applied in large scale.